The future of 64-bit computing will enter a new phase with the release of the Opteron processor by AMD next week.

The Sunnyvale, Calif.-based semiconductor is set to unveil its next-generation, 64-bit AMD Opteron processor (code named Sledgehammer) for servers and workstations on April 22 in New York City.

The x86-64 chip will run at speeds of 1.4GHz, 1.6GHz and 1.8GHz. AMD's other 64-bit chip, the desktop and notebook-oriented Athlon 64 chip codenamed Clawhammer, is scheduled for a September 2003 release.

After various delays, the company says it is ready to take on its chief rival Intel with what is claims is a much better product.

"AMD believes the future of computing, from high-end servers to mainstream desktop and notebook PCs, will be based on pervasive 64-bit computing. We expect to work with our customers and partners to bring the benefits of 64-bit computing to end users worldwide," said AMD executive vice president Rob Herb said late last month.

Radical DesignThe Opteron is radical -- it represents a totally new CPU architecture, system platform, and even microcode support all rolled into one. The Opteron is conservative -- AMD's x86-64 architecture runs current 32-bit applications, and quickly, while giving forward-thinking buyers a transition path to 64-bit computing rather than the start-from-scratch approach of Intel's 64-bit Itanium family.

The 0.13-micron-process silicon-on-insulator Opteron -- a 90-nanometer-process successor will arrive in 2004 -- features two more pipeline stages than AMD's Athlon XP; instructions-per-clock-cycle boosters such as enhanced branch-prediction algorithms and larger translation look-aside buffers; support for the SSE2 streaming multimedia instructions that debuted in Intel's Pentium 4; and up to 1MB of Level 2 cache, all in a new, plus-sized processor die or 940-pin ceramic package. (The Athlon 64 will use a different, 754-pin socket.)

Both the Opteron and Athlon 64 boast 64-bit data and address paths and break through current 32-bit CPUs' 4GB memory addressing cap with 40-bit physical (up to 1 terabyte) and 48-bit virtual (up to 256 terabytes) memory addressing space. The Opteron also supports three HyperTransport links, providing up to 19.2GB/sec of bandwidth, versus the Athlon 64's single HyperTransport link for 6.4GB/sec of data transfer.

AMD says HyperTransport technology helps slash system bottlenecks, boost efficiency and increase system throughput by reducing the number of buses.

In terms of architectural changes, the most noticeable is the Opteron's integrated memory controller -- a 128-bit, dual-channel design supporting DDR266 and DDR333 SDRAM. Both the Opteron's memory controller and the Athlon 64's -- a single 72-bit channel -- take that job away from its traditional place in the system chipset's external Northbridge, greatly reducing the latency of read/write requests. This essentially controls the system at, or yields a front-side bus speed matching, the clock speed of the CPU.

With the new Opteron comes a gutsy new numbering scheme. AMD says the first digit in the model number communicates scalability, and represents the maximum number of processors supported by that model number:

The second and third digits communicate relative performance within each product line. In this case an Opteron Model 244 will offer higher performance than an Opteron chip Model 242.

AMD started numbering the last two digits at 40. The company also says the Model numbers are not directly related to frequency.

It seems obvious that Intel will continue to hold the clock-speed advantage (its Xeon currently peaks at 3.06GHz), while AMD might well win the performance race -- it's shown estimated 32-bit benchmark results that show a 2.0GHz Opteron comfortably ahead of the 2.8GHz Xeon.

SuSE Linux has promised a full 64-bit version of Linux as soon as the Opteron ships, with Red Hat committed to follow a bit later. Even Sun Microsystems is reportedly ready to use Opterons in its blade servers .

Sun's already has a 64-bit - the UltraSPARC. Other 64-bit product brands already available include Hewlett-Packard's PA RISC and Alpha chips as well as and IBM's PowerPC processors.

No one denies that AMD faces an uphill fight against Intel, but there has never been so much buzz surrounding an AMD server processor, nor such promise for truly competitive performance and scalability -- both for entry-level and midrange servers, and for four- and eight-way systems in the $10,000-and-up segment that today's Athlon MP has had to cede to Intel's Xeon MP and Itanium 2.

AMD's "32-bit today, 64-bit tomorrow" strategy should pay off with budget-conscious IT managers, and with one or two big-name server vendors on board and a fairly quick arrival of 64-bit Windows Server, the underdog's gamble could pay off.